This application is related to Japanese application No. 2000-205358 filed on Jul. 6, 2000, whose priority is claimed under 35 USC xc2xa7119, the disclosure of which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a sample suction apparatus. In particular it relates to a so-called piercing apparatus for piercing a plug-sealed specimen vessel with a suction needle (piercer) to suck up a sample.
2. Description of Related Art
To suck up a sample such as blood out of a sealed specimen vessel, commonly employed is a method of sucking up the sample by fixing the specimen vessel and then piercing a plug of the specimen vessel with a suction needle in the shape of an injection needle. Specifically, with respect to the specimen vessel tilted to have its plug lower than its bottom, a vessel supporting means is shifted to abut the bottom of the vessel and then a washing bath for washing the suction needle is shifted to abut the plug to fix the specimen vessel. Then the suction needle penetrates the washing bath and pierces the plug to suck up the sample contained in the vessel (see Japanese Examined Utility Model Publication No. HEI 7(1995)-3328).
In a conventional apparatus as described above, two drive sources (air cylinders) are utilized to independently move the vessel supporting means, the washing bath and the suction needle. If the number of the drive source is reduced, size and production costs of the apparatus are reduced and the control thereof is simplified.
Under such circumferences, the present invention has been achieved to provide an apparatus capable of surely fixing the specimen vessel by sandwiching it at both ends and piercing the plug with the suction needle, utilizing a single drive source.
The present invention provides a sample suction apparatus comprising: a first member, a second member, and a third member capable of linearly reciprocating along the same direction and spaced apart from each other, the second member being located between the first member and the third member; a drive source provided on the third member to enlarge and reduce a distance between the first member and the third member; an elastically compressible spacer inserted between the second member and the third member; and a suction needle provided on the third member, the suction needle pointing to the first member, wherein the drive source reduces the distance between the first member and the third member to perform: a first action of shifting the first member toward the third member to contact the first member with a portion of a specimen vessel; a second action of shifting the second member together with the third member toward the first member to contact the second member with another portion of the specimen vessel so that the specimen vessel is sandwiched between the first and second members; and a third action of shifting the third member toward the first member to compress the spacer to bring the third member close to the second member so that the suction needle is inserted in the specimen vessel.
These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.